Guide roller assembly for motionpicture projectors



July 1, 1947. R. J. MILLER 2,423,334

GUIDE ROLLER ASSEMBLY FOR MOTION PICTURE PROJECTORS Filed June 16, 1942 2 Sheets$heet l 56 58 44 5 54 INVENTOR I Karma/v0 J/f/LLE? i BY XX/WM y 1947' R. J. MILLER 2,423,334

GUIDE ROLLER ASSEMBLY FOR MOTION PICTURE PROJEGTORS Filed June 16f 1942 2 Sheets-Sheet 2 52 /30 F R [/4 l /341 4 /4 \E/ INVENTOR. 72 [2. fmwawo ZN/4:2

Patented July 1, 1947 GUIDE ROLLER ASSEMBLY FOR MOTION- I PICTURE PROJECTORS Raymond J. Miller, Detroit, Mich., assignor to American Pattern and Manufacturing troit, Mich, a copartnership 7 Application June 16, 1942, 'Serial N 0. 447,251

1 Claim. (crawl-ac)" This invention relates to motion picture projectors and more particularly to improved guide rollers for maintaining fiexlible stnip film ,in driving engagement with the driving teeth of film moving sprockets to move the film through the motion picture projector.

Heretofore considerable difiiculty has been experienced in maintaining the strip film in driving engagement with the film moving sprockets. This was particularly true after the projector had been used for a sufficient period of time to wear the guide rollers. These difiiculties were in part due to the fact that no readily operable means were provided to vary the normal operating position of the guide rollers relative to the sprockets, and the fact that the guide rollers were themselves used as actuating levers to move their supporting brackets angularly to move the guide roller relative to the film driving sprockets. These forces exerted through the guide roller supporting shafts and arms subjected the units to undesirable strains which materially reduced their effective life and caused them to lose their adjustments in a relatively short period of time.

An object of this invention is to provide improved guide rollers for motion picture projectors wherein readily operable means are provided to accurately align the guide rollers with the film driving sprockets and to vary the force exerted by the guide roller to maintain the strip film in driving engagement with the film driving sprockets.

A further object of the invention resides in the provision of a cam member which may be detachably clamped in any angularly adjusted position with reference to a film driving sprocket to induce a guide roller carrying arm to maintain a desired adjusted position with reference to a driving sprocket to vary the force required to move the guide roller from an adjusted position with reference to the film driving sprocket.

Another object is to provide a guide roller assembly having an adjustable cam member which may be locked in. any desired position to receive a guide roller carrying assembly which may be detachably mounted on the cam member without varying the adjusted position of the cam member.

A further object of this invention is to provide an eccentric adjustment between a guide roller supporting shaft and a guide roller carrying member whereby the position of the guide roller with reference to the film driving sprocket may be readily varied by merely manipulating the eccentric adjustment of the roller supporting shaft.

Another object is to provide a guide roller assembly having a separate manually operable lever to actuate the guide roller member between operative'and inoperative positions, thereby minimiz- 2 ing the forces and strains to which the guide rollershaft is subjected.-

Still a further object is-to provide readily-adjustable yielding means whereby the force exerted bya guide roller to yieldingly urge'flexible stripfilm towards engagement with a driving sprocket may be readily varied.

Another object is to provide improved-'guid rollers having-internally disposed means foroiling the guide rollers in such a manner that oil is prevented from contacting thefsurface of the film passing throughtheprojector.

Yet a, still-further object of the invention resides in the provision of improved guide roller assemblies having hollow roller supporting shafts whereby lubricant may be supplied to the surfacesbetween the rollers and shafts intermediate-the length of the rollers to lubricate the guide rollers over theirfull length and whereby any excess. oil will be thrown off outside of the marginal edges of the film by centrifugal force exerted onradially extending'flanges carried by the guide rollers v V Yetanother object resides in the provision of a, guide roller assembly which maybe readily removed from a motion picture projector without disturbing the setting of an adjusting guide roller positioning cam adapted to be detachably clamped to a motion picture projector.

' Another object of the inventionresides in the provision of guide rollers adjustable relative to both the guide roller. carrier arms and the film driving sprockets of motion picture projectors.

- A*further object is to. provide a plurality of film guide rollers adjustable relative to each other and to a film driving sprocket.

Other objects and advantages ofthis invention will be apparent fromv the following detailed description considered in connection with the accompanying drawings, submitted for purposes of illustration only, and not intended to define the scope ofthe. invention, reference being had for that purpose to the subjoined claim.

In--the drawings wherein similar reference charactersrefer to similar parts throughout the several views Eig lis a side elevation partly in sectionof a lmotion picture projector embodying the present invention."

looking in the direction of the arrows.

taken-substantially'on the line .33 of Fig. 2,

Fig. 4 is asectional vview taken substantially on the line 4-4 ofFig. 3, looking in the direction of the arrows. r

Fig. 5is an-- exploded view df ai portion of the guide roller actuating mechanism.

aperture pressure plate I) Fig. 6 is a sectional view of a modified. form of guide roller'adjusting cam.

Fig. Tis a view'simila r to Fig. 6 showing a still further modified form of adjusting cam.

Fig. 8 is a fragmentary longitudinal sectional View of a guide roller and shaft assembly show ing one desirable means of lubricating the guide roller.

Fig. 9 is a View similar to'Fig. 8- showing a modified form of lubricating means.

Fig. 10 is a fragmentary longitudinal sectional view of an eccentric connection between a guide.

roller supporting shaft and a guide roller supportmg arm.

Fig. 11 is an end elevation of the device illustratedin Fig. 10.

Fig. 12 is a vertical sectional view illustrating film guide rollers positioned in the aperture plate. Before explaining in detail the present inventionit isto be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings; since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now to Fig; 1, the invention is illustrated as applied to a motion picture projector having a main case It preferably separated by an intermediate wall l2-into a film compartment and a, mechanism compartment. A light source positionedbehind a shutter housing i4 is adapted to direct light through the housing [4 and a rear aperture pressure plate housing l6 having an aperture therein to project successively spaced images from flexible strip film aligned with an aperture inthe housing l6. positioned in the film compartment.

The film is yieldingly maintained in engagement with the members forming the apertureby a pressure plate It. The aperture pressure plate l8 may be moved axially with reference to the aperture; in the pressure plate housing" It by means of amanually operable lever 20-to-facilitate the threading of filmjintq the projector; The projected" images are magnified by a lens positioned in a suitable lens tube assembly 22 and are projected onto a screen positioned forwardly of the projector insuch a manner as to be viewed. The lens assembly may be moved longitudinally relative to theaperture in the housing I6 to focus the projected images by means of a manually 0perably. lens focusing member 24 projecting through the forward case of the housing 10.

Strip film 26 may bedrawn from a suitable film magazine carried by. a r'nagazine adapter 28- and passed over an upper film driving sprocket 30 having a plurality of sprocket driving teeth 32. The film 26 is directed downwardly between the I 'l8' and the housin 16. An intermittently driven sprocket 34 isprovided tcintermittently move the film to alignl successively Spaced film frameswith the aperture positioned in the housing IGto permit projecting light to project the images therefrom to the; screen. After passingv beyond the intermittently driven sprocket the filmis directed over-alower driving sprockettli'having suitable driving teeth 38 and is directed th ough'an opening '4 Mn the bottom" of the housing ID to a sound head preferably positioned belowthe film compartment;

" The m 26 may be maintained contact with the driving teeth 32 of the sprocket 30 by means of a guide roller 42 mounted on a shaft 44 carried by an arm 4% adjustably fastened to the intermediate wall H2. The film 26 may be maintained in contact with the driving teeth 38 of the lower driving sprocket 35 by means of a guide roller assembly having spaced guide rollers 48 and 50 similar tothe guide roller 42 of the upper assembly. It will be understood that a single guide roller may be usedwto maintain the film in driving contact with the lower sprocket 35 if desired and a plurality of guide rollers 42 may be employed to maintain the film in contact with the upper driving sprocket 30.

Since the guide rollers 32, 68 and 58 are substantially identical, only the upper guiding roller will be described in detail. The roller 42 is provided with longitudinally spaced flanges 52 positioned to straddle the driving teeth 32 on each side of the drivingrollers tomaintain the apertures positioned adjacent the edges of the film 26 in contact with the driving teeth 32 of the driving sprocket til, The guide roller 42' is also provided with enlarged flanges 5 positioned ad jacent its ends to lie outside the marginal edges of the film whereby excess lubricating oil will be thrown radially by centrifugal forcev outside of the marginal edges of the film.

The guide roller shaft M. is as illustrated in Figs. 2 and 10 provided with an eccentric projection 56- adaptedto be adjustably clamped by a lock ng screw 53 in an arm 66. The position of the guide roller. 32 and the flanges 52' relative-to the driving sprocket 3i and driving teeth 32 may be varied by oscillating the shaft M. on. its eccentric adjustment to increase or decrease the between the guide roller. and the driving sprocket. 7

Where a plurality of guide rollers areemployed to guide the film with reference to a single driving sprocket such as the guide rollers. 68 and 50, each guide roller may be individually adjusted on its associated eccentric shaft to vary itsposition relative to the other guide roller and relative tothe driving sprocket.

The-- arm 5% is as more clearly illustrated in Figs. and 5 mounted on an. adjustable cam member adapted to be clamped to the intermediate Wail 52 by a screw 65 having. a, threaded head. The cammember 62 has a fiat surface 65 adaptedtobeengaged by a spring 68 positioned in the arm 6 3 and clamped thereto by; means of a screw an. aperture l2 being. provided; in the upper portion of the arm til topermit. access to the screw iii: in the arm. Ed to.sec ur e it..,

The arm. is preferably providedlwitha cylin: drical. portion, hi having longitudinally spaced concentric surfaces. adapted, to enga e the surfaces'i't 'Iitof: themember'filto.iournnli arm fidrelative-tothe calnmember t2 The; guide roller 42 maybe actuated by'meansgof; a separate lever 38 having anactuating portion-,&2 positioned to lie outside of the guide roller 42: whereby it may be readily grasped to actuate the guideroller. A memberis preferably having aqscrew' driller slot-8E may as threaded. on thethreaded head of the stud: st.- to retain the outer end of; the cylindricalportion Asmoreclearly illustratediin Figs. 8:to.l0 ;.the shaft M. is provided with an axiallyextending oiling duct stlextendingto approximately midway of the guide roller The duct 93 communicates witha radiallye: endirigport 92 whereby oilmay be applied to the inner surface of the roller; 42 to lubricate the space between. theiroller 42-. and

g. "in

shaft 44: vOil-thus: depositedwflows axially in both directions to thoroughly lubricate the driving rollers and any excess oil is thrown off by the radially extending flanges 54 positioned outside of the marginal edges of the film 26.

As illustrated in Fig. 8, a ball check valve 94 yieldingly urged by a spring 93 may be provided to maintain lubricant within the port 90, the lubricant being supplied to the port 90 by depressing the ball 94. A snap ring 98 positioned in a groove adjacent the outer end of the shaft 44 may be provided to maintain the guide roller 42 on the shaft 44, A screw driver slot I may be provided to permit oscillation of the shaft 44 to adjust the eccentric projection 56 between the shaft 44 and the arm 60 to vary the spacing of the guide roller with reference to the driving sprocket. When it is desired to actuate the shaft 44 a pronged screw driver may engage the screw driver slot I00, or the ball and spring check valve may be countersunk to permit the use of a nor mal screw driver.

If desired, a screw I04 illustrated in Fig. 9 may be threaded into the outer end of the shaft 44 to maintain the guide roller 42 on the shaft and to maintain lubricant within the port 90.

The guide roller assembly may be removed for cleaning purposes without disturbing the adjustment of the cam member 62. To remove the assembly it is only necessary to take off the member 84 and rotate the arm 60 and cylindrical portion 14 to position the spring 38 in alignment with the radial surface of the member 82. The arm 60 may then be withdrawn from the camming member 62 for cleaning or repair and may be replaced thereon in the same manner without disturbing the spring tension urging the guide roller into engagement with the driving roller. A charnfered portion 63 may be provided to elevate the spring to facilitate assembling the arm 60 on the cam member 62.

Fig. 6 illustrates a modified form of camming member which may be used in lieu of that illustrated in Fig. 5. In this embodiment of the invention it will be noted that a camming member I06 having a V-shaped slot I08 positioned in one side is adapted to be detachably clamped to the intermediate wall I2 by means of the threaded stud 64. A ball I I0 is urged by a spring H2 in a radially extending bore I I4 into engagement with the slot I08 to yieldingly urge the guide roller 42 into a predetermined angular position with reference to the driving sprocket30. The spring H2 is maintained in the bore H4 by means of a threaded plug IIB whereby the force urging the ball into engagement with the slot I08 may be varied to increase or decrease the yielding force urging the guide roller 42 toward the driving roller 30. The inner end of the bore H4 is contracted as illustrated at [I5 to prevent the ball IIO from passing through,

The embodiment of Fig. 7 is similar in many respects to that of Fig. 6, it being noted that a camming member I I8 is provided with a substantially flattened surface I20 adapted to be engaged by a plunger I22 yieldingly urged by a spring I24 into engagement therewith.

Referring now to Fig. 12, it will be observed that guide rollers I 30 and I32 are positioned in the housing I6 and are mounted on a shaft I34 journalled at one end in an arm I38 and a boss I38. The roller I32 is maintained against axial movement by means of a stop I40 clamped to the shaft I34 by a stud I42. The guide roller I30 is yieldingly urged toward the guide roller I32 by means of a spring I44. An internal port I46 terminating in radially extending openings I48 is provided to lubricate the space between the guide rollers I30 and I32 and the shaft I34, a ball check oil cup I50 being provided to close the outer end of the boss I38 in which shaft I34 is journalled. Radially extending flanges I52 carried by the rollers I30 and I32 are provided to discharge oil that seeps through the joint between the rollers to prevent oil from travelling axially to get on the radially extended portions of the rollers I30 and I32 which engage the film.

This is a continuation-in-part of my co-pending application Serial No. 250,310, filed January 11, 1939, now Patent Number 2,312,663, issued March 2, 1943. Features disclosed but not claimed herein are being claimed in my copending application Serial Number 556,683, filed October 2, 1944.

I claim:

In a motion picture projector having a filmdriving roller, a guide roller assembly comprising an arm having one end pivotally mounted in a predetermined space relationship to said filmdriving roller, said arm being movable with respect thereto by application of manual forces, a shaft on the other end of said arm, a guide roller rotatably mounted on said shaft, eccentric adjustment means operatively interposed between said shaft and said arm for adjusting bearing of said guide roller in the operative position thereof against the film and the film-driving roller, a thumb lever provided on said arm intermediate its ends for manually moving said arm and the guide roller into and out of its operative position without exerting and. transmitting the moving force through said eccentric adjustment means, said shaft being shaped to surround partly one end of the guide roller, but clearing the same in disassembly, and thus to interfere and discourage application of manual force directly to said guide roller; and yielding means adapted to maintain said guide roller in its operative position.

RAYMOND J. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,707,839 Beck Apr. 2, 1929 1,957,164 Frappier et a1. May 1, 1934 1,986,180 Bauch Jan. 1, 1935 2,178,208 Loomis et a1 Oct. 31, 1939 1,802,708 Dina Apr. 28, 1931 1,854,004 Tschopp Apr. 12, 1932 2,229,237 Brenkert Jan. 21, 1941 2,031,756 Boecking Feb. 25, 1936 2,164,748 Loomis et a1. July 4, 1939 

